// Code by Heratino & Nelofus
// 何度も 絶望の前で折り返す
// 无数次地，在绝望前折返
#include <bits/stdc++.h>
using i64 = long long;

//{{{
template<typename T>
inline void chkmin(T &a, const T &b) {if (a > b)	a = b;}
template<typename T>
inline void chkmax(T &a, const T &b) {if (a < b)	a = b;}
//}}}

constexpr int N = 2e5 + 10;
std::vector<int> G[N];
inline int query(int x, int y) {
	std::cout << "? " << x << ' ' << y << std::endl;
	int val;
	std::cin >> val;
	return val;
}

int n;
inline void clear() {
	for (int i = 1; i <= n; i++)
		G[i].clear();
}

std::vector<int> cur;
int siz[N];
int mxs[N];

void dfs(int u, int fa) {
	cur.push_back(u);
	siz[u] = 1;
	mxs[u] = 0;
	for (const int &v : G[u]) {
		if (v == fa)
			continue;
		dfs(v, u);
		siz[u] += siz[v];
		chkmax(mxs[u], siz[v]);
	}
}

inline void solve() {
	mxs[0] = 1e9;
	std::cin >> n;
	clear();
	int rt = -1;
	for (int u = 1; u <= n; u++) {
		int x, y;
		std::cin >> x >> y;
		if (x != 0)	G[u].push_back(x), G[x].push_back(u), rt = u;
		if (y != 0)	G[u].push_back(y), G[y].push_back(u), rt = u;
	}
	assert(rt != -1);
	while (true) {
		cur.clear();
		dfs(rt, 0);

		if (cur.size() == 1) {
			std::cout << "! " << cur[0] << std::endl;
			return ;
		}

		if (cur.size() == 2) {
			if (query(cur[0], cur[1]) == 0)
				std::cout << "! " << cur[0] << std::endl;
			else
				std::cout << "! " << cur[1] << std::endl;
			return ;
		}

		for (const int &x : cur)
			chkmax(mxs[x], siz[rt] - siz[x]);
		for (const int &x : cur)
			if (mxs[x] < mxs[rt])
				rt = x;

		dfs(rt, 0);
		int mx1 = 0, mx2 = 0;
		for (const int &v : G[rt]) {
			if (siz[v] > siz[mx1])
				mx2 = mx1, mx1 = v;
			else if (siz[v] > siz[mx2])
				mx2 = v;
		}
		int p = query(mx1, mx2);
		if (p == 0) {
			G[mx1].erase(std::find(G[mx1].begin(), G[mx1].end(), rt));
			rt = mx1;
		} else if (p == 1) {
			G[rt].erase(std::find(G[rt].begin(), G[rt].end(), mx1));
			G[rt].erase(std::find(G[rt].begin(), G[rt].end(), mx2));
		} else if (p == 2) {
			G[mx2].erase(std::find(G[mx2].begin(), G[mx2].end(), rt));
			rt = mx2;
		} else {
			assert(0);
		}
	}
}

int main() {

	int T;
	std::cin >> T;
	while (T--)
		solve();
	return 0;
}
// もう一度繋ぐ星の絆 奇跡起こせる
// 再一次连结起来的星星的羁绊 能够将奇迹引发